Semiconductor device

Abstract

Provided is a metal-oxide semiconductor (MOS) transistor containing a metal gate pattern. The semiconductor device includes a p-channel metal-oxide semiconductor (PMOS) transistor including a semiconductor substrate, a first insulating film formed on the semiconductor substrate, a first metal gate conductive film formed on the first insulating film, and a nitrogen diffusion blocking film formed between the first insulating film and the first metal gate conductive film, and an n-channel metal-oxide semiconductor (NMOS) transistor including the semiconductor substrate, a second insulating film formed on the semiconductor substrate, a second metal gate conductive film formed on the second insulating film, and a reaction blocking film formed of metal nitride and formed between the second insulating film and the second metal gate conductive film. According to the inventive concept, a reaction between a metal gate film and an insulating film may be minimized so as to result in a highly reliable MOS transistor.

1 . A semiconductor device comprising p-channel metal-oxide semiconductor (PMOS) and n-channel metal-oxide semiconductor (NMOS) transistors,
 wherein the PMOS transistor comprises:   a semiconductor substrate;   a first insulating film formed on the semiconductor substrate;   a first metal gate conductive film formed on the first insulating film; and   a nitrogen diffusion blocking film formed between the first insulating film and the first metal gate conductive film,   wherein the NMOS transistor comprises:   the semiconductor substrate;   a second insulating film formed on the semiconductor substrate;   a second metal gate conductive film formed on the second insulating film; and   a reaction blocking film formed of metal nitride and formed between the second insulating film and the second metal gate conductive film.   
     
     
         2 . The semiconductor device of  claim 1 , wherein the nitrogen diffusion blocking film comprises metal carbide or nitrogen-free metal. 
     
     
         3 . The semiconductor device of  claim 2 , wherein the metal carbide or the nitrogen-free metal comprises titanium (Ti), tantalum (Ta), titanium silicide (TiSi), or tantalum silicide (TaSi). 
     
     
         4 . The semiconductor device of  claim 1 , wherein the metal nitride is nitrogen-rich metal nitride and comprises Ti or Ta. 
     
     
         5 . The semiconductor device of  claim 1 , wherein the first and second insulating films comprise one selected from the group consisting of silicon oxide (SiO 2 ), silicon oxynitride (SiO x1 N y1 ), hafnium oxide (HfO 2 ), hafnium oxynitride (HfO x2 N y2 ), hafnium silicon oxide (HfSi x3 O y3 ), hafnium silicon oxynitride (HfSi x4 O y4 N z4 ), zirconium oxide (ZrO 2 ), zirconium oxynitride (ZrO x5 N y5 ), zirconium silicon oxide (ZrSi x6 O y6 ), zirconium silicon oxynitride (ZrSi x7 O y7 N z7 ), tantalum oxide (Ta 2 O 5 ), tantalum oxynitride (TaO x8 N y8 ), tantalum silicon oxide (TaSi x9 O y9 ), tantalum silicon oxynitride (TaSi x10 O y10 N z10 ), aluminum oxide (Al 2 O 3 ), aluminum oxynitride (AlO x11 N y11 ), aluminum silicon oxide (AlSi x12 O y12 ), aluminum silicon oxynitride (AlSi x13 O y13 N 13 ), titanium oxide (TiO 2 ), titanium oxynitride (TiO x14 N y14 ), titanium silicon oxide (TiSi x15 O y15 ), titanium silicon oxynitride (TiSi x16 O y16 N z16 ), and combinations thereof, wherein the subscripts x1 to z16 are positive real numbers. 
     
     
         6 . The semiconductor device of  claim 1 , further comprising a capping layer formed directly on or under the first and second insulating films, wherein the capping layer is an oxide film comprising lanthanum (La), aluminum (Al), or magnesium (Mg). 
     
     
         7 . The semiconductor device of  claim 1 , wherein the semiconductor substrate under the first and second insulating films comprises silicon carbide (SiC) or silicon germanium (SiGe). 
     
     
         8 . The semiconductor device of  claim 1 , wherein the first and second metal gate conductive films comprise the same material. 
     
     
         9 . The semiconductor device of  claim 1 , wherein the first and second metal gate conductive films comprise different materials. 
     
     
         10 . The semiconductor device of  claim 1 , wherein the first and second metal gate conductive films comprise one selected from the group consisting of tantalum (Ta), titanium (Ti), titanium nitride (TiN), tungsten (W), nickel (Ni), tantalum silicon (TaSi), tungsten silicon (WSi), titanium silicon (TiSi), molybdenum silicon (MoSi), nickel silicon (NiSi), ruthenium (Ru), ruthenium oxide (RuO), iridium (Ir), iridium oxide (IrO), and platinum (Pt). 
     
     
         11 . The semiconductor device of  claim 1 , wherein the metal nitride is nitrogen-rich metal nitride in which the content of nitrogen is greater than the content of stoichiometric nitrogen. 
     
     
         12 . The semiconductor device of  claim 1 , wherein the PMOS transistor further comprises the reaction blocking film formed between the nitrogen diffusion blocking film and the first metal gate conductive film. 
     
     
         13 . The semiconductor device of  claim 12 , wherein the reaction blocking film of the PMOS transistor is positioned higher on the semiconductor substrate than the reaction blocking film of the NMOS transistor. 
     
     
         14 . A p-channel metal-oxide semiconductor (PMOS) transistor comprising:
 a semiconductor substrate;   a gate insulating film formed on the semiconductor substrate;   a metal gate conductive film formed on the gate insulating film; and   a nitrogen diffusion blocking film formed between the gate insulating film and the metal gate conductive film.   
     
     
         15 . The PMOS transistor of  claim 14 , wherein the nitrogen diffusion blocking film comprises metal carbide or nitrogen-free metal. 
     
     
         16 . The PMOS transistor of  claim 15 , wherein the metal carbide or the nitrogen-free metal comprises titanium (Ti), tantalum (Ta), titanium silicide (TiSi), or tantalum silicide (TaSi). 
     
     
         17 . The PMOS transistor of  claim 14 , further comprising a reaction blocking film formed of metal nitride and formed between the nitrogen diffusion blocking film and the metal gate conductive film. 
     
     
         18 . An n-channel metal-oxide semiconductor (NMOS) transistor comprising:
 a semiconductor substrate;   a gate insulating film formed on the semiconductor substrate;   a metal gate conductive film formed on the gate insulating film; and   a reaction blocking film formed of metal nitride and formed between the gate insulating film and the metal gate conductive film.   
     
     
         19 . The NMOS transistor of  claim 18 , wherein the metal nitride is nitrogen-rich metal nitride in which the content of nitrogen is greater than the content of stoichiometric nitrogen. 
     
     
         20 . The NMOS transistor of  claim 18 , wherein the metal nitride is nitrogen-rich metal nitride and comprises Ti or Ta.